1. Field of the Invention
The present invention relates to a communication network managing system, an element manager and a network manager for the use in the system, and a computer-readable recording medium in which a communication network management program is recorded.
2. Description of the Related Art
Nowadays, a communication network is constructed using a variety of base technologies (transmission methods), such as SDH (Synchronous Digital Hierarchy), PDH (Presiochronous Digital Hierarchy), ATM (Asynchronous Transfer Mode), WDM (Wavelength Division Multiplex) and IP (Internet Protocol). And the communication network is divided into subnetworks in a many variety of topologies, such as access networks, core networks, PDH networks and SDH networks. The communication network is thus complicated. Consequently these individual domains that constitute the communication network are managed by element managers or agents called EMSs (Element Management Systems), and these element managers are concentratedly managed by a network manager called NMS (Network Management System). Thus management of the whole communication network is accomplished.
In the conventional network management, however, partly because in the conventional connection-less network, such as IP network, QoS (Quality of Service) has not been guaranteed, and communication traffic running through plural domains depends on the QoS capability of those domains, communication service guaranteeing the requested QoS cannot be provided until the requested QoS is satisfied in all the domains without exception.
For the same reasons, the user's requested QoS cannot also be sufficiently guaranteed by TV conference and voice application for which guarantee of the request QoS is significant, and audio-visual (picture and voice) applications, such as Video on Demand, for which applications guarantee of the requested QoS is fairly significant, and other applications which need real-time performance.
As a hypothetical attempt, collecting the individual QoS capability one for each of the individual units, through which communication traffic (user data) travels, by the above-mentioned element manager (EMS) and then selecting a unit satisfying the requested QoS as an element through which communication traffic runs, could be suggested. But this would consume huge time to perform network control on an end-to-end basis.